Electric bicycles are conventionally driven by means of an electric motor which is powered for operation by an electric battery incorporated in the structural assembly of the bicycle.
To that end, a common solution for incorporating the electric battery for powering the propulsion drive motor in electric bicycles is to hold the electric battery with a fastener of any type in an external position on the bicycle frame. This has the drawback of the electric battery being exposed to easy manipulations and theft by third parties, as well as to the harmful effects of atmospheric agents.
To eliminate this drawback, solutions of integrating the electric battery inside one of the elements making up the bicycle frame have been developed, such as the embodiment proposed in patent document WO03/022671, for example, in which an electric battery is arranged inside the down tube of the bicycle frame, so the electric battery is protected and concealed, overcoming the drawbacks of solutions in which the electric battery is arranged externally on the bicycles. Nevertheless, in this solution the electric battery is mounted in a fixed manner inside the down tube of the frame, which makes it difficult to dismount and replace the electric battery in the event of maintenance, and makes it necessary to take the entire bicycle to a charging connection in order to charge the electric battery. Furthermore, access to the electric battery is made through the lower part of the down tube of the frame, which makes it necessary to turn the bicycle upside down if access to the electric battery is required, with the subsequent structural damage the handlebar and saddle may experience in the process.
Patent document WO99/26837 proposes another solution for incorporating an electric battery inside the down tube of a bicycle frame, the electric battery being inserted through the lower part of the down tube of the frame which converges in the bottom bracket of the bicycle, wherein the housing of the electric battery is closed with a cap which is coupled in the opening of the housing. This solution makes it easier to remove the electric battery in order to take it to a charging connection point for charging, without having to move the bicycle to the charging site; however, it has the drawback that to establish the housing of the battery, the bottom bracket of the bicycle must be moved so that it is mounted in a position above or below the point at which the bars forming the bicycle frame converge, so the bottom bracket is mounted in a manner that is less resistant than in a conventional bicycle, in addition to the necessary structural modification of the bicycle for said mounting.
Additionally, since the housing of the electric battery in the lower part of the bicycle frame is sealed closed, it is also necessary to lift the bicycle or turn it upside down to remove the electric battery, with the subsequent difficulty and damage which the handlebar and saddle may experience in the removal process when the bicycle is turned upside down; furthermore, removal from the lower part requires disassembling the rear wheel damper in order to rotate it so that it does not interfere with the battery during the removal (in the case of a bicycle with rear suspension) or to make a geometry consisting of a long, unwieldy rear (in the case of a bicycle without rear suspension). On the other hand, if the sealing cap of the housing comes off while riding the bicycle, the electric battery can fall out and break, as well as cause an accident.